ALSFRS-R

A structured tour of the ALSFRS-R: its twelve items across four functional domains, why feasibility and sensitivity to change made it the field’s standard outcome measure for twenty-five years, and a frank account of the psychometric limitations that have accumulated against it.

Clinical trials in ALS live or die by their outcome measures. This opening piece of the series frames the measurement problem in neurodegeneration — biological versus functional endpoints — and sets up why the ALSFRS-R became the field’s default answer to it.